<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>布局学习</title>
</head>

<body>
    <div id="top">
        <div id="top-center">
            这是中间的部分
        </div>
    </div>
    <div id="menu">这是菜单</div>
</body>
<style>
    * {
        margin: 0;
        padding: 0;
    }

    ul li {
        list-style: none;
    }

    a {
        text-decoration: none;
    }

    i {
        font-style: normal;
    }



    #top {
        width: 100%;
    }

    #top-center {
        border: 1px solid red;
        max-width: 1200px;
        margin: 0px auto;
    }

    #menu {
        width: 100%;
    }
</style>

</html>